/* ---------------------------- dom/iterator.js ----------------------------- */
(function() {

   var beginWhitespaceRegex = /^[\r\n\t ]+$/,
      // Ignore bookmark nodes.(#3783)
      bookmarkGuard = VED.dom.walker.bookmark( false, true ),
      whitespacesGuard = VED.dom.walker.whitespaces( true ),
      skipGuard = function( node ) {
         return bookmarkGuard( node ) && whitespacesGuard( node );
      };

   // Get a reference for the next element, bookmark nodes are skipped.
   function getNextSourceNode( node, startFromSibling, lastNode ) {
      var next = node.getNextSourceNode( startFromSibling, null, lastNode );
      while ( !bookmarkGuard( next ) )
         next = next.getNextSourceNode( startFromSibling, null, lastNode );
      return next;
   }

   var iterator = new Class({
      initialize: function( range ) {
         if ( arguments.length < 1 )
            return;

         this.range = range;
         this.forceBrBreak = 0;

         // Whether include <br>s into the enlarged range.(#3730).
         this.enlargeBr = 1;
         this.enforceRealBlocks = 0;

         this._ || ( this._ = {} );
      },

      getNextParagraph: function( blockTag ) {
         blockTag = blockTag || 'p';

         // Block-less range should be checked first.
         if ( !VED.dtd[ this.range.root.getName() ][ blockTag ] )
            return null;

         // The block element to be returned.
         var block;

         // The range object used to identify the paragraph contents.
         var range;

         // Indicats that the current element in the loop is the last one.
         var isLast;

         // Indicate at least one of the range boundaries is inside a preformat block.
         var touchPre;

         // Instructs to cleanup remaining BRs.
         var removePreviousBr, removeLastBr;

         // This is the first iteration. Let's initialize it.
         if ( !this._.started ) {
            range = this.range.clone();

            // Shrink the range to exclude harmful "noises" (#4087, #4450, #5435).
            range.shrink( VED.NODE_ELEMENT, true );

            touchPre = range.endContainer.hasAscendant( 'pre', true ) || range.startContainer.hasAscendant( 'pre', true );

            range.enlarge( this.forceBrBreak && !touchPre || !this.enlargeBr ? VED.ENLARGE_LIST_ITEM_CONTENTS : VED.ENLARGE_BLOCK_CONTENTS );

            if ( !range.collapsed ) {
               var walker = new VED.dom.walker( range.clone() ),
                  ignoreBookmarkTextEvaluator = VED.dom.walker.bookmark( true, true );
               // Avoid anchor inside bookmark inner text.
               walker.evaluator = ignoreBookmarkTextEvaluator;
               this._.nextNode = walker.next();
               // TODO: It's better to have walker.reset() used here.
               walker = new VED.dom.walker( range.clone() );
               walker.evaluator = ignoreBookmarkTextEvaluator;
               var lastNode = walker.previous();
               this._.lastNode = lastNode.getNextSourceNode( true );

               // We may have an empty text node at the end of block due to [3770].
               // If that node is the lastNode, it would cause our logic to leak to the
               // next block.(#3887)
               if ( this._.lastNode && this._.lastNode.type == VED.NODE_TEXT && !this._.lastNode.getText().trim() && this._.lastNode.getParent().isBlockBoundary() ) {
                  var testRange = this.range.clone();
                  testRange.moveToPosition( this._.lastNode, VED.POSITION_AFTER_END );
                  if ( testRange.checkEndOfBlock() ) {
                     var path = new VED.dom.elementPath( testRange.endContainer, testRange.root );
                     var lastBlock = path.block || path.blockLimit;
                     this._.lastNode = lastBlock.getNextSourceNode( true );
                  }
               }

               // Probably the document end is reached, we need a marker node.
               if ( !this._.lastNode ) {
                  this._.lastNode = this._.docEndMarker = range.document.createText( '' );
                  this._.lastNode.insertAfter( lastNode );
               }

               // Let's reuse this variable.
               range = null;
            }

            this._.started = 1;
         }

         var currentNode = this._.nextNode;
         lastNode = this._.lastNode;

         this._.nextNode = null;
         while ( currentNode ) {
            // closeRange indicates that a paragraph boundary has been found,
            // so the range can be closed.
            var closeRange = 0,
               parentPre = currentNode.hasAscendant( 'pre' );

            // includeNode indicates that the current node is good to be part
            // of the range. By default, any non-element node is ok for it.
            var includeNode = ( currentNode.type != VED.NODE_ELEMENT ),
               continueFromSibling = 0;

            // If it is an element node, let's check if it can be part of the
            // range.
            if ( !includeNode ) {
               var nodeName = currentNode.getName();

               if ( currentNode.isBlockBoundary( this.forceBrBreak && !parentPre && { br:1 } ) ) {
                  // <br> boundaries must be part of the range. It will
                  // happen only if ForceBrBreak.
                  if ( nodeName == 'br' )
                     includeNode = 1;
                  else if ( !range && !currentNode.getChildCount() && nodeName != 'hr' ) {
                     // If we have found an empty block, and haven't started
                     // the range yet, it means we must return this block.
                     block = currentNode;
                     isLast = currentNode.equals( lastNode );
                     break;
                  }

                  // The range must finish right before the boundary,
                  // including possibly skipped empty spaces. (#1603)
                  if ( range ) {
                     range.setEndAt( currentNode, VED.POSITION_BEFORE_START );

                     // The found boundary must be set as the next one at this
                     // point. (#1717)
                     if ( nodeName != 'br' )
                        this._.nextNode = currentNode;
                  }

                  closeRange = 1;
               } else {
                  // If we have child nodes, let's check them.
                  if ( currentNode.getFirst() ) {
                     // If we don't have a range yet, let's start it.
                     if ( !range ) {
                        range = this.range.clone();
                        range.setStartAt( currentNode, VED.POSITION_BEFORE_START );
                     }

                     currentNode = currentNode.getFirst();
                     continue;
                  }
                  includeNode = 1;
               }
            } else if ( currentNode.type == VED.NODE_TEXT ) {
               // Ignore normal whitespaces (i.e. not including &nbsp; or
               // other unicode whitespaces) before/after a block node.
               if ( beginWhitespaceRegex.test( currentNode.getText() ) )
                  includeNode = 0;
            }

            // The current node is good to be part of the range and we are
            // starting a new range, initialize it first.
            if ( includeNode && !range ) {
               range = this.range.clone();
               range.setStartAt( currentNode, VED.POSITION_BEFORE_START );
            }

            // The last node has been found.
            isLast = ( ( !closeRange || includeNode ) && currentNode.equals( lastNode ) );

            // If we are in an element boundary, let's check if it is time
            // to close the range, otherwise we include the parent within it.
            if ( range && !closeRange ) {
               while ( !currentNode.getNext( skipGuard ) && !isLast ) {
                  var parentNode = currentNode.getParent();

                  if ( parentNode.isBlockBoundary( this.forceBrBreak && !parentPre && { br:1 } ) ) {
                     closeRange = 1;
                     includeNode = 0;
                     isLast = isLast || ( parentNode.equals( lastNode ) );
                     // Make sure range includes bookmarks at the end of the block. (#7359)
                     range.setEndAt( parentNode, VED.POSITION_BEFORE_END );
                     break;
                  }

                  currentNode = parentNode;
                  includeNode = 1;
                  isLast = ( currentNode.equals( lastNode ) );
                  continueFromSibling = 1;
               }
            }

            // Now finally include the node.
            if ( includeNode )
               range.setEndAt( currentNode, VED.POSITION_AFTER_END );

            currentNode = getNextSourceNode( currentNode, continueFromSibling, lastNode );
            isLast = !currentNode;

            // We have found a block boundary. Let's close the range and move out of the
            // loop.
            if ( isLast || ( closeRange && range ) )
               break;
         }

         // Now, based on the processed range, look for (or create) the block to be returned.
         if ( !block ) {
            // If no range has been found, this is the end.
            if ( !range ) {
               this._.docEndMarker && this._.docEndMarker.remove();
               this._.nextNode = null;
               return null;
            }

            var startPath = new VED.dom.elementPath( range.startContainer, range.root );
            var startBlockLimit = startPath.blockLimit,
               checkLimits = { div:1,th:1,td:1 };
            block = startPath.block;

            if ( !block && startBlockLimit && !this.enforceRealBlocks && checkLimits[ startBlockLimit.getName() ] && range.checkStartOfBlock() && range.checkEndOfBlock() && !startBlockLimit.equals( range.root ) )
               block = startBlockLimit;
            else if ( !block || ( this.enforceRealBlocks && block.getName() == 'li' ) ) {
               // Create the fixed block.
               block = this.range.document.createElement( blockTag );

               // Move the contents of the temporary range to the fixed block.
               range.extractContents().appendTo( block );
               block.trim();

               // Insert the fixed block into the DOM.
               range.insertNode( block );

               removePreviousBr = removeLastBr = true;
            } else if ( block.getName() != 'li' ) {
               // If the range doesn't includes the entire contents of the
               // block, we must split it, isolating the range in a dedicated
               // block.
               if ( !range.checkStartOfBlock() || !range.checkEndOfBlock() ) {
                  // The resulting block will be a clone of the current one.
                  block = block.clone( false );

                  // Extract the range contents, moving it to the new block.
                  range.extractContents().appendTo( block );
                  block.trim();

                  // Split the block. At this point, the range will be in the
                  // right position for our intents.
                  var splitInfo = range.splitBlock();

                  removePreviousBr = !splitInfo.wasStartOfBlock;
                  removeLastBr = !splitInfo.wasEndOfBlock;

                  // Insert the new block into the DOM.
                  range.insertNode( block );
               }
            } else if ( !isLast ) {
               // LIs are returned as is, with all their children (due to the
               // nested lists). But, the next node is the node right after
               // the current range, which could be an <li> child (nested
               // lists) or the next sibling <li>.

               this._.nextNode = ( block.equals( lastNode ) ? null : getNextSourceNode( range.getBoundaryNodes().endNode, 1, lastNode ) );
            }
         }

         if ( removePreviousBr ) {
            var previousSibling = block.getPrevious();
            if ( previousSibling && previousSibling.type == VED.NODE_ELEMENT ) {
               if ( previousSibling.getName() == 'br' )
                  previousSibling.remove();
               else if ( previousSibling.getLast() && previousSibling.getLast().$.nodeName.toLowerCase() == 'br' )
                  previousSibling.getLast().remove();
            }
         }

         if ( removeLastBr ) {
            var lastChild = block.getLast();
            if ( lastChild && lastChild.type == VED.NODE_ELEMENT && lastChild.getName() == 'br' ) {
               // Take care not to remove the block expanding <br> in non-IE browsers.
               if ( VED.env.ie || lastChild.getPrevious( bookmarkGuard ) || lastChild.getNext( bookmarkGuard ) )
                  lastChild.remove();
            }
         }

         // Get a reference for the next element. This is important because the
         // above block can be removed or changed, so we can rely on it for the
         // next interation.
         if ( !this._.nextNode ) {
            this._.nextNode = ( isLast || block.equals( lastNode ) || !lastNode ) ? null : getNextSourceNode( block, 1, lastNode );
         }

         return block;
      }
   });

   VED.dom.range.implement({
      createIterator: function() {
         return new iterator( this );
      }
   });
})();




